Pfizer Handbook of Microbial Metabolites 322 



674 L-(+)-a-Aminobutyric Acid, C4H9O0N, colorless crystals, m.p. 



270-280° (dec), [a]ir" +8.0° (c 1.0 in water). 



CH3— CHo— CH— COOH 



I 

 NH2 



Escherichia coli, Corynebacterium diphtheriae 



A. Poison, Nature 161 351 (1948). 



Elizabeth Work, Biochim. et Biophys. Acta 3 400 (1949). 



675 L-Threonine, C4H9O3N, colorless crystals, m.p. 255-257° (dec), 



[a]D-'" -28.3° (c 1.1 in water). 



CH3— CH— CH— COOH 



I I 

 OH NHo 



Widely distributed. 



676 S-Methyl-L-cysteine, C4H,,03NS, colorless crystals, m.p. --164° 



(dec), [alo'' +125° (c 2.5 in water). 



CH3— S— CH>— CH— COOH 



NHo 



Neurospora crassa 



James B. Ragland and James L. Livermore, Arch. Biochem. 

 and Biophys. 65 574 (1956). (Isolation from neurospora) 



Clayton J. Morris and John P. Thompson, /. Am. Chem. 

 Soc. 78 1605 (1956). (Physical properties) 



677 4-Imidazolyacetic Acid, C-.H^OoN^, colorless needles (Hydrate), 



m.p. 222° (dec). 



N C— CH2— COOH 



II II 



HC CH 



H 



Polyporus sulfureus 



P. H. List, Planta Med. 6 424 (1958). 



678 Azaserine (Diazoacetyl-L-serine), C-,H704N;^, light yellow-green 



crystals, dec 146-162°, [a],,"' '' -0.5° (c 8.46 in water at 

 pH 5.18). 



N.— CH— CO— O— CH,— CH— COOH 



NH, 

 An unclassified streptomycete 



